This invention relates generally to medical imaging systems. More specifically, this invention relates to real time display of complex medical images obtained with a medical imaging system.
Doctors and technicians commonly employ medical imaging systems to obtain, display, and study images for diagnostic purposes. In ultrasound imaging systems, for example, a doctor may obtain heart images in an attempt to learn whether the heart functions properly. In recent years, these imaging systems have become very powerful, and often include the capability to display a looping series of ultrasound images.
The looping series of images appears to the viewer as a short repeating movie or video of the internal structures imaged during a series of ultrasound firings. In a cardiology examination, for example, the imaging system may capture ultrasound images of the heart. In the past, however, the time and space presentation of such images has been limited because of the time-consuming processing (including firing ultrasound beams, receiving the beams, and beamforming) associated with generating the images.
While it would be beneficial in many instances for a doctor to view a rapid or real-time image sequence of a three dimension region over a significant section of anatomy, such display has typically not been possible. Generally, as the size or resolution of the three dimensional volume showing the region is increased, the slower the ultrasound system obtained and displayed the three dimensional volume. Conversely, as the size or resolution of the three dimensional volume was decreased, the faster the ultrasound system could obtain and display the three dimensional volume.
However, at the point where the ultrasound system could acquire and display three dimensional volumes in real-time, the anatomical region that was imaged was too small in size or resolution to be diagnostically useful. Thus, prior ultrasound systems were limited to slowly displaying large regions or high resolutions, or quickly displaying small regions (without sufficient content) or low resolutions quickly. In other words, in three dimensional imaging in particular, there was a limit to how large of an image could be acquired and displayed in real-time with sufficient resolution in time and space while presenting clinically relevant data.
More recently, ultrasound systems have become available that acquire and display three dimensional ultrasound images assembled from multiple lines of ultrasound data. Due to both system limitations and physical limitations related to the speed of sound, only a limited number of ultrasound lines can be acquired simultaneously. These lines must be closely spaced so that the spatial resolution of the volume is sufficient for clinical use. With these restrictions it is only possible to acquire a limited volume with any rapidity.
One technique for compensating for the physical limitations in acquiring ultrasound data, was to acquire several sequences (cineloops) of sub-volumes. The sub volumes could be combined together in order to create a larger image which could be displayed after the acquisition of all the sub-volumes was finished (see for example, U.S. Pat. No. 6,544,175 to Richard M. Newman). Thus, ultrasound data acquired in different heart cycles (but at the same time relative to the heart cycle) were displayed together. However, this technique suffers from a significant drawback in that the display of the full image is done only after the acquisition of all of the sub-volumes. During acquisition; only data from the presently acquired subregion is displayed. Thus, the doctor or technician performing the acquisition only obtains limited diagnostic information during acquisition.
Therefore, there is a need for systems and methods that address the difficulties set forth above and others previously experienced.